1. Field of the Invention
The present invention relates to microwave packages, and more particularly, to such packages including microwave susceptors for providing conduction heating to the contents thereof.
2. Description of the Prior Art
Microwave ovens possess the ability to heat, cook or bake certain items, particularly food stuffs, extremely rapidly. Unfortunately, microwave heating also has its disadvantages. For example, microwave heating alone in today's microwave ovens often fails to achieve such desirable results as browning and crispening. Contemporary approaches to achieving these and other desirable results with microwave ovens include the use of microwave susceptors.
Generically, microwave susceptors are devices which when disposed in a microwave energy field such as exists in a microwave oven, respond by generating a significant amount of heat. The susceptor absorbs a portion of the microwave energy and converts it directly to heat which is useful, for example, to crispen or brown food stuffs. Although several mechanisms can be responsible for a microwave susceptor's ability to convert microwave energy directly to heat, the most commercially successful microwave susceptors to date are so-called thin filmed susceptors which rely on resistive, i.e., I.sup.2 R, losses to generate heat. These thin film susceptors generally consist of a plastic sheet which has a thin layer of conductive or semiconductive metal coated thereon.
The prior art consists of a myriad of microwave packages which utilize microwave susceptors. For example, U.S. Pat. No. 4,891,482 issued to Jaeger et al. on Jan. 2, 1990 discloses a package which includes a sleeve which has a microwave susceptor located thereon. During cooking in the microwave the food product is surrounded by the microwave susceptor and the susceptor is adapted to provide increased heat at the lower surface of the food product.
U.S. Pat. No. 4,777,053 issued on Oct. 11, 1988 to Tobelmann et al. discloses a package which has upper and lower microwave susceptors located in contact with opposing sides of the food to be heated. The susceptors are spaced from external shield layers by a corrugated layer.
U.S. Pat. No. 4,713,510 issued to Quick et al. on Dec. 15, 1987 discloses a package incorporating a susceptor layer adjacent a solid paperboard layer in contact with the food to be heated.